What CATEGORY does it fall into?

You must know the actual weight of your drone before a flight. Any changes to an RPA (a different lens, a new battery, a sticker!) could move you from one weight category to another – the commercial name of the RPA, the weight at purchase, what you “thought” it weighed. are all irrelevant. As the pilot, YOU are responsible for what you have in the air and for operating that equipment safely and legally.